newbie needs advice

[HamNCheese <sorry_no_e-mail@xxxxxxxx>]

I'm looking to have an alarm system put in for my house, nice
residential area in the Los Angeles area.  Concerned both about
robbery as well as home invasion (there have been a couple of
incidents nearby of people tied up in their homes and robbed at
gunpoint).

What kind of response is best?  Is police response worth anything...
or is an alarm company's security response worth anything either?  Am
I better off just having a loud siren to hopefully scare off the punks
and forgetting about having anyone respond?

The installers all seem to use wireless.  How reliable is this?  I
have many doors and windows and wiring them all would be extremely
expensive.